WO2020038608A1

WO2020038608A1 - Air separation system, method for low-temperature separation of air, and method for creating an air separation system

Info

Publication number: WO2020038608A1
Application number: PCT/EP2019/025278
Authority: WO
Inventors: Stefan Lochner
Original assignee: Linde Aktiengesellschaft
Priority date: 2018-08-22
Filing date: 2019-08-20
Publication date: 2020-02-27
Also published as: EP3614082A1

Abstract

The invention relates to an air separation system (100-700) comprising four separation units (1-4) in the form of a high-pressure column (1), a base section (2) of a two-part low-pressure column, the top section (3) of the two-part low-pressure column and a single-part argon production column (4), which has a top condenser (5a), wherein the four separation units (1-4) are connected to one another at least partially by means of lines (6) and/or are connected to one or more further devices (7, 8) at least partially by means of lines (6), wherein the lines (6) comprise one or more first lines and multiple second lines, wherein the one or more first lines is/are one or more lines that feed into a top region of the base section (2) of the low-pressure column, and/or a line that feeds into a gas compartment of a top condenser (5a) of the argon production column (4). According to the invention, the top section (3) of the low-pressure column has a smaller cross-section than the base section (2) of the low-pressure column, and vertically running sections of the second lines are accommodated at least partially in a cold box (20a, 40, 40a), which is designed as a column cold box (20a) in which the top section (3) of the low-pressure column is arranged, or designed as a separate line cold box (40, 40a) in which none of the four separation units (1-4) are arranged. The invention also relates to a corresponding method for the low-temperature separation of air and a method for creating a corresponding air separation system (100-700).

Description

description

Luftzerleaunasanlaae, process for low-temperature zerleauna of air and process for building an air separation plant

The present invention relates to an air separation plant, a method for the low-temperature separation of air by means of a corresponding air separation plant and a method for the construction of a corresponding air separation plant.

State of the art

The production of air products in liquid or gaseous state by low-temperature separation of air in air separation plants is known and

for example at H.-W. Häring (ed.), Industrial Gases Processing, Wiley-VCH,

2006, in particular Section 2.2.5, "Cryogenic Rectification".

Air separation plants have rectification column systems, which as

Two-column systems, in particular as classic Linde double-column systems, but can also be designed as three- or multi-column systems. In addition to the

Rectification columns for the production of nitrogen and / or oxygen in the liquid and / or gaseous state, ie the rectification columns for nitrogen-oxygen separation, rectification columns for the production of further air components, in particular argon, can be provided.

The rectification columns of the rectification column systems mentioned are operated at different pressure levels. Known double column systems have a so-called high pressure column (also referred to as a pressure column, medium pressure column or lower column) and a so-called low pressure column (also referred to as an upper column). The high-pressure column is typically operated at a pressure level of 4 to 7 bar, in particular approximately 5.3 bar. The low pressure column is operated at a pressure level of typically 1 to 2 bar, in particular approximately 1.4 bar. In certain cases, higher pressure levels can also be used in the low pressure column. The pressures specified here and below are absolute pressures at the top of the columns specified. In known methods and systems for the low-temperature separation of air, an oxygen-enriched and nitrogen-depleted liquid is formed in a lower region of the high-pressure column and drawn off from the high-pressure column. This liquid, which in particular also contains argon, is at least partly fed into the low-pressure column and further separated there. You can before

Feed into the low-pressure column are at least partially evaporated, with evaporated and non-evaporated portions at different positions in the

Low pressure column can be fed.

The present invention is based on a method or a corresponding system in which a high and a low pressure column is used.

In the context of the present invention, however, the low-pressure column is not formed in one piece, but is divided into a first section and a second section, the first and the second section at different positions

Air separation plant and are arranged at different heights and

Do not project onto each other, especially in a top view of a longitudinal axis of the column. However, the first and the second section of the low pressure column are operated at a common pressure level within the scope of the present invention. The used in the context of the present invention, divided into two sections

Low-pressure column differs from also known arrangements in which, in addition to the high-pressure and low-pressure columns, a further column for separating nitrogen and oxygen is provided, which, however, is operated at a pressure level which lies between the pressure levels at which the high-pressure column and the Low pressure column operated. A two-part low pressure column is also disclosed in CN 202 853 259 U and in Research Diosclosure 430, February 1, 2000, Kenneth Mason Publications.

Air separation plants with raw and pure argon columns can be used to obtain argon. An example is illustrated by Häring (see above) in Figure 2.3A and described from page 26 in the section "Rectification in the Low-pressure, Crude and Pure Argon Column" and from page 29 in the section "Cryogenic Production of Pure Argon". As explained there, argon accumulates at a certain height in the low-pressure column in corresponding plants. At this or at another convenient point, possibly below the argon maximum, the

Low pressure column of argon enriched gas with an argon concentration of typically 5 to 15 mole percent are withdrawn and transferred to the crude argon column. A corresponding gas typically contains about 0.05 to 100 ppm nitrogen and otherwise essentially oxygen. It should be expressly emphasized that the values given for the gas drawn off from the low pressure column are only typical example values.

The crude argon column essentially serves to separate the oxygen from the gas drawn off from the low-pressure column. The separated oxygen in the crude argon column or a corresponding oxygen-rich fluid can be returned to the low-pressure column in liquid form. The oxygen or the oxygen-rich fluid is typically fed into the low-pressure column a number of theoretical or practical trays below the feed point for the liquid which has been drawn off from the high-pressure column, enriched with oxygen and depleted with nitrogen and possibly at least partially evaporated. With a two-part

Low pressure column, the gas enriched in argon is particularly at the

Separation point between the parts removed and the oxygen or that

oxygen-rich fluid fed back at this point.

A gaseous fraction which remains in the crude argon column and essentially contains argon and nitrogen is separated further in the pure argon column to obtain pure argon. The raw and pure argon columns point

Top condensers, in particular with a portion of those withdrawn from the high pressure column, enriched in oxygen and depleted in nitrogen

Liquid can be cooled, which partially evaporates during this cooling. Other fluids can also be used for cooling.

In principle, a pure argon column can also be dispensed with in corresponding systems, typically ensuring that the

Nitrogen content at the argon transition is below 1 ppm. However, this is not a mandatory requirement. In this case, argon of the same quality as a conventional pure argon column becomes the raw argon column or a comparable column

typically somewhat lower than that conventionally in the

Pure argon column transferred fluid withdrawn, the floors in the section between the crude argon condenser, that is, the top condenser of the crude argon column, and a corresponding deduction serve in particular as barrier bottoms for nitrogen. The The present invention can be used with such an arrangement without a pure argon column. Since the raw argon column or a comparable column in such an arrangement is already used for the production of pure argon and not for

Raw argon production is used, is also referred to below as an "argon production column". An argon recovery column can be a conventional crude argon column (which is used with or without a pure argon column) or a corresponding crude argon column modified for obtaining pure argon.

When creating air separation plants that are set up for argon extraction, problems arise due to the dimensions of the columns used.

A double column system for nitrogen-oxygen separation of conventional type can reach a height of almost 75 m. Corresponding air separation plants can therefore no longer be prefabricated because the respective component groups can generally no longer be transported over longer distances. This means that they have to be created at the respective destination. This is disadvantageous for various reasons, among other things because appropriate personnel at the destination are either unavailable or expensive. The effort to create appropriate

Air separation plants increase significantly.

US 2015/096327 A1 describes a transportable unit for one

Low-temperature air separation plant is known, which has a main heat exchanger for cooling feed air and a double column for separating the cooled feed air, the double column comprising a high-pressure column and a low-pressure column, which are arranged one above the other. The transportable unit comprises a cold box, in the interior of which accessories of the double column, in particular pipes and valves, but not the double column and not the main heat exchanger, are arranged, the transportable unit having connections for connecting the pipes to the double column and to the main heat exchanger.

EP 1 180 655 A1 discloses a cryogenic air separation plant with several modules, which comprise at least one heat exchanger unit, a pressure column and a low pressure column, as well as with the accessories belonging to the respective modules and with at least two cold boxes in which the modules and / or the accessories are arranged , At least one of the cold boxes is designed as a main box and at least one of the cold boxes is designed as a secondary box, the secondary box Contains at least one of the modules and the accessories of the module arranged in the secondary box are predominantly in the main box.

It is desirable to have a largely modularized air separation plant at the manufacturing site. The individual components are preferably already accommodated there in the corresponding cold boxes and only have to be connected to one another at the destination. Modules, so-called piping skids, can advantageously also be used for this.

Disclosure of the invention

Against this background, the present invention proposes an air separation plant, a method for the low-temperature separation of air by means of a corresponding air separation plant and a method for producing a corresponding one

Air separation plant with the features of the independent claims. Preferred embodiments are the subject of the dependent claims and the following description.

Before the features and advantages of the present invention are explained, some basics of the present invention are explained in more detail and terms used below are defined.

The devices used in an air separation plant are described in the technical literature cited, for example from Häring (see above) in Section 2.2.5.6, "Apparatus". If the following definitions do not deviate from this, express reference is made to the cited technical literature for the language used in the context of the present application.

Liquids and gases can, in the language used here, be rich or poor in one or more components, "rich" for a content of at least 50%, 75%, 90%, 95%, 99%, 99.5%, 99, 9% or 99.99% and "poor" for a maximum of 50%, 25%, 10%, 5%, 1%, 0.1% or 0.01% on a mole, weight or volume basis , The term "predominantly" can correspond to the definition of "rich". Liquids and gases can also be enriched or depleted in one or more components, these being Terms refer to a content in a source liquid or gas from which the liquid or gas was obtained. The liquid or gas is "enriched" if this or this content is at least 1.1 times, 1.5 times, 2 times, 5 times, 10 times 100 times or 1,000 times the content, and " depleted "if this or this contains at most 0.9 times, 0.5 times, 0.1 times, 0.01 times or 0.001 times the content of a corresponding component, based on the starting liquid or the starting gas. If, for example, "oxygen", "nitrogen" or "argon" is mentioned here, this should also be understood to mean a liquid or a gas which is rich in oxygen or nitrogen, but does not necessarily have to consist exclusively of it.

The present application uses the terms “pressure level” and “temperature level” to characterize pressures and temperatures, which is intended to express that corresponding pressures and temperatures in a corresponding system do not have to be used in the form of exact pressure or temperature values to realize the inventive concept. However, such pressures and temperatures are typically in certain ranges, for example ± 1%, 5% or 10% around an average.

Corresponding pressure levels and temperature levels can lie in disjoint areas or in areas that overlap one another. In particular, pressure levels include, for example, unavoidable or expected pressure drops. The same applies to temperature levels. For those given here in cash

Pressure levels are absolute pressures.

The high-pressure column and the low-pressure column (or, in the context of the present invention, its first section) of an air separation plant are in heat-exchanging connection via a so-called “main condenser”. The

Main capacitor can in particular in a lower (sump) area of the

Low pressure column (or here from its first section) can be arranged. In this case it is a so-called internal main condenser and the evaporation space of the main condenser is also the interior of the

Low pressure column (or from its first section). However, the main condenser can basically be arranged outside the interior of the high-pressure column, that is to say a so-called external main condenser. A rectification column system of an air separation plant is arranged in one or more cold boxes. A "cold box" is understood here to mean an insulating sheath that covers a heat-insulated interior except for bushings

Pipes and the like completely covered with outer walls. Plant parts to be insulated are arranged in the interior, for example one or more

Rectification columns and / or heat exchangers. The insulating effect can be brought about by appropriate design of the outer walls and / or by filling the space between the system parts and outer walls with an insulating material. In the latter variant, a powdery material such as pearlite is preferably used. Both the rectification column system of a plant for the low-temperature separation of air and the main heat exchanger and other cold plant parts such as pipes, valves and instrumentation are typically enclosed by one or more cold boxes. The external dimensions of the cold box usually determine the transport dimensions.

A "main heat exchanger" of an air separation plant is used to cool the feed air in indirect heat exchange with return flows from the

Rektifikationssäulensystem. It can be formed from a single or a plurality of heat exchanger sections connected in parallel and / or in series, for example from one or more plate heat exchanger blocks. Separate heat exchangers, which are used specifically for the evaporation or pseudo-evaporation of a single liquid or supercritical fluid, without heating and / or evaporation of another fluid, are not part of the main heat exchanger.

A "subcooler" or "subcooling counterflow" is, in the parlance used here, a heat exchanger through which gaseous and liquid material flows in an air separation plant are used to exchange heat

are subjected to one another, which are removed from the rectification column system and at least partially returned to the rectification column system after the heat exchange.

The relative spatial terms "above", "below", "above", "below", "above",

"Below", "next to", "next to each other", "vertical", "horizontal" etc. refer here to the spatial orientation of the rectification columns of an air separation plant in normal operation. Under an arrangement of two rectification columns or others Components "on top of each other" are understood here to mean that the upper end of the lower of the two apparatus parts is at a lower or the same geodetic height as the lower end of the upper of the two apparatus parts and the projections of the two apparatus parts overlap in a horizontal plane. In particular, the two parts of the apparatus are arranged exactly one above the other, that is to say the axes of the two parts of the apparatus run on the same vertical straight line. However, the axes of the two parts of the device do not have to lie exactly vertically one above the other, but can also be offset from one another, in particular if one of the two parts of the device, for example a rectification column or a column part with a smaller diameter, is to have the same distance from the sheet metal jacket of a cold box as another with a larger one Diameter.

Typically, conventional rectification trays or structured packings with a packing density of, for example, 250 to 750 m ² / m ³ are used in air separation plants. In the following, the terms "specific surface area of a pack" and "pack density" are used synonymously. A denser packing therefore has a higher specific surface area than a less dense one.

Advantages of the invention

The present invention is based on the knowledge that a specific arrangement of different rectification columns or of sections of corresponding rectification columns in different cold boxes and, in particular, their advantageous dimensioning and / or subdivision makes it possible in certain cases to provide corresponding cold boxes with the rectification columns contained therein or the ones contained therein Prepare sections of rectification columns (hereinafter also generally referred to as "separation units") and deliver them in a prefabricated state to the place of manufacture of a corresponding air separation plant

transport. In certain embodiments of the present invention, corresponding units can be completely prefabricated; However, in other configurations it is also possible to prefabricate only the part of the cold boxes that can be provided with corresponding transport dimensions and to transport them to the place of manufacture, whereas other components of a corresponding air separation plant are manufactured on site. any Combinations of prefabrication and on-site production are possible. A particular advantage in the context of the present invention results from advantageous

Arrangement options for part of the lines of a corresponding system.

Overall, the present invention proposes an air separation plant with four separation units in the form of a high-pressure column (first separation unit), one

Base section of a two-part low-pressure column (second separation unit), the top section of the two-part low-pressure column (third separation unit) and a one-part argon recovery column (fourth separation unit), which has a top condenser, the four separation units at least in part by means of lines to one another and / or are connected at least in part by means of lines to one or more further apparatuses.

The argon recovery column can be designed, in particular, as a conventional crude argon column, in which case a component mixture referred to as crude argon in customary usage is removed. It can be in the

Argon recovery column is also a modified crude argon column, to which fluid is supplied from one or both parts of the low-pressure column, but pure argon is removed directly. In the first case, a pure argon column is typically present, in the second case, not. The other apparatuses can in particular be a main heat exchanger of the air separation plant and a subcooling counterflow. The four separation units can also be connected to one another, for example, by means of corresponding lines via such a further apparatus as a supercooling counterflow.

A "two-part" low-pressure column is understood to mean in particular a corresponding rectification column in which two sections can be arranged spatially separated from one another. In plan view, corresponding sections of a two-part rectification column do not project, or do not project completely, onto one another, and corresponding sections are in particular also not arranged in a common outer shell. The term "formed in two parts" thus delimits corresponding configurations from structural units in which

Components are structurally connected to one another permanently (ie not only via lines) and cannot be arranged separately from one another, as is the case here in the case of the argon recovery column. The "foot section" and "head section" here refer to the sections of a two-part rectification column which function in their function, in particular with regard to the fractions or material flows occurring there, to the lowest or uppermost sections of conventional, one-piece designs

Rectification columns correspond. A foot section has, for example, a sump container, and a head section has, for example, a head condenser. The top section is thus the part of a corresponding rectification column, which is connected to a corresponding top condenser, and in which a return flow is applied to the corresponding rectification column. In a one-piece low-pressure column of known air separation plants, an oxygen-rich liquid fraction is obtained in the sump, which can be drawn off as an oxygen product. This also takes place in the sump of a foot section of a two-part low-pressure column. The foot section of the two-part low-pressure column is therefore also referred to as the "oxygen section". At the head of a one-piece low-pressure column of known air separation plants, a gaseous nitrogen product can be drawn off, the same applies to the upper part of a head section of a two-piece low-pressure column. The sections of a "two-part" rectification column (foot and head section) are connected to one another by means of lines and possibly pumps, in order in this way to represent an operation which is also possible with a one-part column.

In the context of the present invention, the head section of the low-pressure column has a smaller cross section (or diameter) than the foot section of the

Low pressure column, which is achieved in particular by using a lower packing density. The use of a lower packing density increases the required and practically realized height of the head section of the low pressure column with a simultaneously smaller cross section. In conventional

Air separation plants would not consider reducing the packing density to the person skilled in the art, since this would greatly increase the plant height. However, the aim is to increase the packing density. In the present invention, in which the low-pressure column is divided into two and components are provided in separate cold boxes, particular advantages result from such a configuration, since in this way the

Head section of the low pressure column advantageously with other components of the Distillation column system can be housed in a common cold box and requires a smaller footprint ..

In the air separation plant proposed according to the invention there is a

Packing density in the head section of the low-pressure column advantageously less than 600 m ² / m ³ , in particular 100 to 500 m ² / m ³ , and in the foot section of the

Low pressure column at more than 300 m ² / m ³ , in particular at 600 to 1,500 m ² / m ³ . The packing density in the head section of the low pressure column is advantageously lower than in the foot section. Due to this different equipment of the

Head section and the foot section of the low pressure column results in a greater height of the head section with a smaller cross section with the advantages explained.

In the context of the present invention, a distinction is made between the lines with regard to their arrangement in a cold box, as explained below. The lines comprise one or more first lines and several second lines, the terms “first” and “second” lines here only for the purpose of distinction

corresponding lines can be used with respect to the arrangement mentioned. The one or more first lines is or are one or more

Lines which lead into a head region of the foot section of the low pressure column and in particular transport gas from the head region of the foot section of the low pressure column into a lower region of the head section of the low pressure column and / or the argon recovery column, and / or a pipe which leads into a gas space of an evaporation chamber of a head condenser of the argon recovery column opens, and the gas, in particular the corresponding gas, is transported into a central region of the head section of the low-pressure column. The second lines include in particular all or part of the lines mentioned above, which do not represent the first lines. These are in particular:

Gas lines connected to the top section of the low pressure column and liquid lines to and from an existing supercooling counterflow. If present, the pure argon column also has a plurality of lines with a corresponding number of control valves for the reboiler and one

Capacitor control on. These can also be "second lines" in the sense used here, as can lines for an argon transport pump which may be present. Basically, an air separation plant with cryogenic separation units of the type previously explained, but in contrast to the present invention with a two-part crude argon column, is known from EP 2 965 029 B1. In the context of the present invention, however, it was recognized that a prefabrication of

Corresponding cold boxes is also possible without the division of an argon recovery column such as a crude argon column and the associated additional outlay on equipment, in particular the provision of pumps for transferring fluid between the sections of such a crude argon column. The present invention, in its different advantageous configurations explained below, also allows partial or complete prefabrication of components of a corresponding air separation plant without the need to split the crude argon column in two.

According to the invention it is provided that vertically running sections of the second lines are at least partially housed in a cold box, which as

Column cold box in which the head section of the low pressure column is arranged, or as a separate line cold box in which none of the four separation units mentioned (but possibly a further separation unit as explained below) is arranged. The term "column cold box" is used here to characterize a cold box which has at least one of the separation units mentioned. A "line cold box", on the other hand, preferably serves to hold corresponding lines, but can also have a further separation unit in the form of a pure argon column, as explained below.

The two alternatives of the present invention are connected to one another by the common inventive idea that a particularly advantageous arrangement of corresponding components can also be achieved in a system with a one-part argon recovery column such as a crude argon column, the present invention, in particular the smaller dimensions, according to the first alternative makes use of a head section of a low-pressure column, which can be suitably adapted for this purpose in terms of packaging, as a result of which the second lines or their named sections can be accommodated in a corresponding column cool box. Housing the second lines or their sections in a separate piping gold box also leads to the advantages which can be achieved according to the invention. By providing the second lines or their named sections in a separate cold box, that is to say using one Line gold box, a larger part of the assembly work can be relocated from the construction site to the workshop, as the mentioned column gold box with the additional line sections may no longer be transportable.

As mentioned, in the context of the present invention the second lines or their mentioned sections are at least partially housed in a corresponding cold box. However, one or more vertically extending sections of the first line or of the plurality of first lines can also be accommodated in the cold box, in which the vertically extending sections of the second lines are at least partially accommodated, if this is advantageous for manufacturing reasons, for example.

If the separate line cold box is provided, separation units and other apparatuses can be arranged in different ways within the scope of the present invention, for example to ensure transportability or prefabricability or, if these are not possible, advantageous production on the construction site and / or particularly space-saving To allow arrangement and / or a reduction of line lengths and the associated manufacturing costs.

In addition to the separate line gold box, a common column gold box can be provided in which all of the four separation units are accommodated. Such a common pillar gold box is typically not transportable and is therefore advantageously manufactured on the construction site. As part of this

However, the separate piping gold box is provided, the piping work on the construction site can nevertheless be significantly reduced by appropriate prefabrication. In this context, further instrumentation, in particular temperature, pressure and quantity measuring devices as well as analysis points, can be relocated with corresponding advantages to this line cold box.

The embodiment of the present invention, in which all four separating units are arranged in a common pillar gold box, can, in a particularly preferred embodiment, which is explained below, in particular to reduce the steel construction effort due to the optimized surface of a

lead common outer shell of all components. In this embodiment, the separation units are preferably arranged in such a way that their longitudinal axes are parallel to one another, as is customary in the art. The longitudinal axes run in the direction of a maximum extension of the separation units. The longitudinal axes can coincide with the central axes of the separation units; corresponding separation units can, however, also be constructed asymmetrically. The separation units can, however, in the sense of the above

Explanations can be arranged at different heights. In the context of the present invention, in particular the high-pressure column and the foot section of the two-part low-pressure column are permanently connected to one another, in particular their column sleeves being welded to one another. Since the high pressure column typically has a smaller diameter than the low pressure column, no accommodation is typically provided in a common column jacket; the column jacket of the high-pressure column is attached to the lower side of the column jacket of the foot section of the low-pressure column.

In the context of the present invention, it is provided to arrange the line gold box and the column gold box with the four separation units in four quadrants in a projection onto a plan plane that is perpendicular to the longitudinal axes of the separation units, so that in a first of the quadrants at least the major part of the high-pressure column and the foot section of the two-part design

Low-pressure column one above the other, in a second of the quadrants at least the major part of the head section of the low-pressure column, in a third of the quadrants at least the major part of the argon recovery column and in a fourth of the four quadrants the line gold box are arranged. The separating units mentioned are surrounded in their respective quadrants by the common column cool box.

If we are talking about a floor plan level, this means a level on which the elements mentioned can be projected. Not all components have to be cut or present in all planes perpendicular to the longitudinal axes of the separating units; this is not the case in particular if different separating units have different heights and therefore do not extend over the entire height, or, as in the case of the high-pressure column and the

Base section of the low pressure column, these elements are arranged one above the other. In the projection onto the floor plan level, however, you will find all

superimposed elements. A "projection onto the floor plan level" corresponds to a plan view along the longitudinal axes mentioned.

If the term "quadrants" in a corresponding plane is used here, these are regions separated from one another by imaginary lines intersecting perpendicularly in the plane. These do not have to be in the form of structurally separate departments. The respective separation units can also protrude from their assigned quadrant or occupy only part of a corresponding quadrant. This is expressed in the context of this description by the fact that "at least the major part" of the respectively specified elements is arranged in a corresponding quadrant. This at least predominant part comprises in particular more than 75%, 80% or 90% of the respective base area.

In the context of the present invention, the first to fourth quadrants can be arranged in the plan view, in particular clockwise around a center point. In other words, the quadrants in which the

Separation units are arranged or their common pillar gold box is arranged, lie in three adjacent quarters of the floor plan and the

Line cold box can be placed in the remaining quarter.

In particular, the line gold box and the common column gold box with the separating units can be projected onto the floor plan level within one

Rectangle with four side lines may be arranged, which includes a partial area of each of the quadrants, the partial area of the first and second quadrant on a first, the partial area of the second and third quadrant on a second, the partial area of the third and fourth quadrant on a third and the Subareas of the fourth and first quadrants rest on a fourth of the side lines. A first dividing line lying in the floor plan level, on the left side of which the first and the second quadrant and on the right side the third and fourth quadrant are arranged, lies between and parallel to the first and the third side line and a second line running in the floor plan level The dividing line, which is perpendicular to the first dividing line and has the second and third quadrants on its left side and the fourth and first quadrants on its right side, lies between and parallel to the second and fourth sidelines. In a preferred embodiment of the invention, the rectangle can in particular also be square.

In the embodiment just explained, the separating units are arranged in their respective quadrants and the surrounding pillar gold box in an L shape, the line gold box being arranged at an inner angle of the L. In particular, the line gold box and the separation units or their common column gold box can be surrounded with a common outer shell, the projection of which onto the

Floor plan level at least in a section of the rectangle with the four

Sidelines is limited. In particular, however, it is also possible to use only the

To surround separating units with a common outer shell in the form of their column-shaped gold box, the projection of which on the floor plan level is then at least L-shaped in a section, this L being in an inner angle outside the

The outer casing is then arranged in the line gold box.

In an air separation plant designed according to the invention, the

Separation units, that is, without the line gold box being arranged together in a column gold box, which has a recess in the fourth quadrant in the projection onto the floor plan level, in which the projection onto the

Floor plan, the line gold box is arranged. The line cold box can also have a rectangular cross section when projected onto the plan level and can rest on the third and fourth side lines. Depending on the connection requirements, the corresponding side surfaces can be opened or closed.

In a further embodiment, in addition to the separate line gold box, a common column gold box is provided, in which the high pressure column, the

Base section of the low-pressure column and exactly one more of the four separation units are accommodated, a further column cool box being provided in which the remaining of the four separation units is accommodated. This additional pillar gold box can in particular be prefabricated.

In addition to the separate line cold box, however, in a further embodiment of the present invention, a common column cold box can also be provided, in which (only) the high-pressure column and the foot section of the low-pressure column, preferably in a common column jacket or in interconnected fashion separate column jackets, are included, a further common pillar gold box is provided in which the two remaining of the four

Separation units are included.

Instead of the further common pillar gold box, two separate pillar gold boxes can also be used. So it can be in addition to the separate

Line cold box, a common column cold box can be provided in which (only) the high pressure column and the foot section of the low pressure column, in particular in the connection mentioned, are accommodated, in which case two further column cold boxes are provided, in each of which one of the two remaining four separation units is accommodated are. As mentioned, the respective configuration is based in particular on the prefabricability and

Transportability and the available transport options.

In all cases, the foot section of the low-pressure column and the head section of the low-pressure column are preferably arranged next to one another at different geodetic heights and in the sense explained. In particular, a lowest point is in a column interior of the foot section of the low-pressure column above a lowest point in a column interior of the head section of the

Low-pressure column. The geodesic heights where the lowest point in the

Column interiors of the foot section of the low-pressure column on the one hand and the lowest point in the column interior of the head section of the low-pressure column on the other hand are more different than the geodetic heights at which the lowest point in the column interior of the high-pressure column on the one hand and the lowest point in the column interior of the head section of the low-pressure column

on the other hand are arranged. As a result, the arrangement has a lower overall height than in conventional cases.

In the air separation plant proposed according to the invention, a

Raw argon column as the argon recovery column and a pure argon column as a fifth separation unit can be provided, wherein the pure argon column can be accommodated in the line gold box or in that of the column gold boxes, in the green argon column

(in particular the raw argon column and no other separation units)

is recorded. In both cases, the small size results in

Pure argon column, which can therefore be accommodated in a corresponding cold box, one particularly advantageous use of space. Especially when through the

If a pure argon column is arranged in a common column gold box with the raw argon column, which would no longer be transportable or if a corresponding column gold box as a prefabricated unit can no longer be transported even without a pure argon column, the pure argon column is advantageously housed in the separate pipeline gold box, since this allows the degree of prefabrication to be increased , However, as mentioned, the present invention can also

Provide pure argon extraction without a separate pure argon column. In this case, the argon recovery column is modified in the manner described and is used for the direct recovery of pure argon with a content of 100 to 0.1 ppm nitrogen and oxygen. In any case, the argon recovery column is fed with fluid from the foot or head section of the low pressure column at an appropriate pressure level.

In the air separation plant proposed according to the invention, a separation unit set up for the enrichment or extraction of a krypton / xenon or helium / neon mixture can also be provided as a fifth separation unit, this fifth separation unit being able to be accommodated in the line cold box or in that of the column cold boxes, in the crude argon column (in particular the crude argon column and no other separation units) is included. The advantages are similar to those of one

corresponding arrangement of a pure argon column.

Instead of using a two-part crude argon column, as is known from the prior art, the

Packing density of the argon recovery column can be increased so that it can be built smaller and can therefore be accommodated together with other separating units in a column cold box or in a separate, transportable column gold box. In particular, a packing density of more than 750 square meters per cubic meter can be used in a corresponding argon recovery column. In this way, it becomes possible, in particular, to transport a corresponding pillar cool box

Train dimensions. In the context of the present invention, a top condenser of the crude argon column is advantageously designed in such a way that a corresponding cold box becomes portable, in particular with a diameter of less than 4 meters. The present invention makes it possible to build at least part of the piping in the form of the lines mentioned as a transportable unit, as a result of which the work on the construction site can be reduced. An air separation plant designed according to the invention can, if a separate line cold box is provided, in particular have a separate main heat exchanger gold box in which the main heat exchanger of the air separation plant is accommodated, one of the side surfaces of the line gold box assigning a side surface of the main heat exchanger gold box. In this way, the connections from the main heat exchanger to the separating units and vice versa can be accommodated at least for the most part in the line cold box and prefabricated accordingly.

In the case just explained, it is particularly advantageous if an arrangement is made in such a way that at least one further of the side surfaces of the

Line cable box each assigns one side surface of one of the column gold boxes. If a column gold box is provided which contains all of the four separation units mentioned, this is arranged in particular on the side surface of the line gold box which is opposite the side surface which the main heat exchanger cold box assigns. If several pillar gold boxes are provided, these are advantageously distributed around the line gold box. Any of the cold boxes explained can be connected to one another on their surfaces, for example to facilitate joint transport or to reduce insulation losses. In particular, side faces of a line gold box and a main heat exchanger gold box can be arranged parallel to one another, it also being possible to interpose a column gold box for one or more separation units.

If a separate line cold box is provided in an air separation plant according to the invention, it has a size of less than 6 meters, in particular less than 4.8 meters, in particular less than 4.2 meters, in particular in an extension direction. This enables easy transport taking into account typical clearance heights of bridges and the like. A corresponding separate line cold box can in particular also have a subcooling counterflow of the air separation plant. This can be done in a corresponding

Line gold box can be arranged to save space. In contrast to an arrangement in a main heat exchanger cold box, as is also possible, both cold boxes (line and main heat exchanger cold box) easier or even portable. The separate line cold box can in particular be designed in such a way that it extends in a first direction parallel to the vertically running sections of the second lines by at least a factor of 1.5 greater than in the directions vertical to it. The extension in the direction parallel to the vertically running sections of the second lines is in particular more than 20 m and the extension in the directions perpendicular thereto, for example 5 m in each case.

It should be understood that the present invention relates in particular to arrangements in which the high-pressure column and the foot section of the low-pressure column form a solid structural unit with one another. In particular, the respective column jackets can be welded together. The corresponding separation units are therefore permanently and permanently connected to one another. In particular, the high-pressure column and the foot section of the low-pressure column can have the same or different cross-section, whereas the head section of the low-pressure column can in particular be designed with a smaller cross-section if a packing with a lower density is used here. This enables the already mentioned arrangement of the head section of the low pressure column up to a certain diameter in a column cool box, which also

contains corresponding sections of the second lines, in the corresponding embodiment of the invention.

Because a corresponding head section of the low pressure column typically has a lower height than an argon recovery column such as a crude argon column and / or the common unit of high pressure column and foot section of the

Low pressure column, can also be in a column cool box

Subcooling counterflow can be arranged, advantageously below the top portion of the low pressure column. If the low-pressure column has a comparatively small diameter, as is the case in the context of the present invention, it can in particular be arranged together with the second lines mentioned and the supercooling countercurrent in a corresponding column cool box. With a medium diameter, the

Hypothermia counterflow arranged in the pillar gold box, but the second lines outside in the line gold box. With a larger diameter of the low pressure column, however, the Hypothermia counterflow and the second lines in the separate line cold box outsourced.

Here, before and after, we are talking about the vertically running

Sections of the second lines are "at least partially" accommodated in their respective cold boxes, this can in particular be a predominant part of corresponding sections, that is to say in particular at least 50%, at least 60%, at least 80%, at least 90% or at least 95% the respective length. As already mentioned, other apparatuses are also accommodated in the corresponding cold box, in particular in the separate line cold box. This is particularly an instrumentation for flow, temperature and pressure measurement.

Appropriate devices are prefabricated as far as possible, i.e. The measuring lines are laid from the respective cryogenic pipelines through the sheet metal jacket of the cold box. Optionally, these are already installed on the box

Transmitters connected

As already mentioned, the present invention enables, in particular, a two-part design of a crude argon column or a modified one

Dispense raw argon column. This is ensured in particular by the fact that different packing densities are used in the top section of the low-pressure column and the crude argon column. It is particularly advantageous here if a first is located in a lower region of the foot section of the low-pressure column

Pack area is formed with a first packing density and in the

Argon recovery column a second packing area is formed with a second packing density, the first packing density in particular less than 1000 square meters per cubic meter and the second packing density more than 750

Square meters per cubic meter. The second packing density is at least 250 square meters per cubic meter larger than the first packing density. In other words, the crude argon column is packed more densely than the lower region of the foot section of the low-pressure column, and the crude argon column can therefore, as explained above, be formed with a lower height.

Advantageously, for the fluid transfer between a lower region of the head section of the low-pressure column and an upper region of the foot section of the low-pressure column, one or more transfer pumps arranged in parallel and / or redundantly provided transfer pumps can be provided. For example, three transfer pumps each delivering 50% of the required pump output can be provided.

The present invention further relates to a method for the low-temperature separation of air, which is characterized in that an air separation system is used, as has been explained above in various configurations. In this

Process is fed into the high pressure column. A bottom liquid with an oxygen content of 30 to 50 mole percent is formed in the high-pressure column and at least partially transferred to the foot section of the low-pressure column. A top gas is formed in the foot section of the low pressure column and at least partially transferred into the argon recovery column and / or into the top section of the low pressure column. A bottom liquid is formed in the argon recovery column and at least partially transferred to the top section of the low-pressure column. A bottom liquid is formed in the top section of the low-pressure column and in a lower region of the crude argon column and / or in an upper region of the

Transferred foot section of the low pressure column.

A method for creating an air separation plant, which is also proposed according to the invention, as explained above in embodiments, comprises four separation units in the form of a high-pressure column, a foot section of a two-part low-pressure column, a head section of the two-part low-pressure column and a one-part argon recovery column

provided and the four separation units are connected at least in part by means of lines to one another and / or to one or more further apparatuses, the lines comprising one or more first lines and several second lines, the one or more first lines one or more lines that open into a head region of the foot section of the low-pressure column and / or a line that opens into a gas space of a head condenser of the argon recovery column. According to the invention, it is provided that vertically running sections of the second lines are at least partially accommodated in a cold box, which is designed as a column cold box, in which the head section of the low-pressure column is arranged, or as a separate line cold box, in which none of the four separation units is arranged. As mentioned, the first lines can also be arranged accordingly. The prefabrication of the within the scope of the present invention includes, in particular, prefabricating one or more pillar gold boxes with the respective separation units and / or the line gold box at a first geographical position, transporting them to a second geographical position, and using the air separation plant at the second geographical position to create the cold boxes. Any pre-fabricated cold boxes can be created in this way.

The present invention is explained in more detail below with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention.

Brief description of the drawings

Figure 1 illustrates an air separation plant according to an embodiment of the present invention in a schematic partial representation.

Figure 2 illustrates an air separation plant according to an embodiment of the present invention in a schematic partial representation.

Figure 3 illustrates an air separation plant according to an embodiment of the present invention in a schematic partial representation.

Figure 5 illustrates arrangements of cold boxes in air separation plants according to another embodiment of the present invention.

Figure 6 illustrates arrangements of cold boxes in air separation plants according to another embodiment of the present invention.

FIG. 7 illustrates arrangements of cold boxes in air separation plants according to a further embodiment of the present invention. Detailed description of the drawings

FIG. 1 shows an air separation plant, which is set up for operation according to an embodiment of the present invention, in a greatly simplified partial illustration. The air separation plant includes other components and is shown here in a highly simplified form as 100.

The air separation plant 100 has a high-pressure column 1, a two-part system

formed low pressure column with a foot section 2 and a head section 3, a one-piece raw argon column 4 and a pure argon column 5. The high-pressure column 1, the foot section 2 of the low-pressure column, the head section 3 of the low-pressure column, the crude argon column 4 and the pure argon column 5 each represent "separation units" in the parlance used here and are at least partially connected to one another by means of lines, which are summarized here with 6 connected to other apparatuses such as a supercooling counterflow 7 and a main heat exchanger, not shown here.

With regard to the functioning of the illustrated components of the air separation plant 100, which is well known from the prior art, reference is expressly made to the specialist literature cited at the beginning. In the illustrated here

Air separation plant 100, air in the form of a material flow A is fed into the high-pressure column 1. The air can in particular by means of a not shown

Main air compressor and optionally one or more post-compressors or boosters, also not shown, are compressed and, e.g. adsorptive, purified, and cooled in the main heat exchanger, not shown. The use of several compressed, purified and cooled air streams is also known. Some of these can also be fed into the foot and / or head section 2, 3 of the low-pressure column and, if necessary, relaxed to an appropriate pressure level or provided at different pressure levels.

In the air separation plant 100 shown here, a sump liquid with an oxygen content of 30 to 50 mole percent is formed in the high-pressure column 1 and at least partially in the form of a material flow B into the head section 3 of FIG

Transferred low pressure column. The stream B or partial streams thereof can be used to cool the top condensers 4a and 5a of the raw and pure argon columns 4, 5 be used. Alternatively, any other medium that is drawn off between the sump and the top of the high-pressure column 1 can also be used.

A top gas is formed in the foot section 2 of the low pressure column and partly in the form of a material flow C into the crude argon column 4 and partly in the form of a

Material flow D transferred into the head section 3 of the low pressure column. In the

A crude argon column 4 is formed and transferred at least partially in the form of a stream E into the foot section 2 of the low-pressure column. A bottom liquid is formed in the head section 3 of the low-pressure column, which is transferred here in the form of a material flow F into a lower region of the crude argon column 4. This bottom liquid can then be transferred as part of the already mentioned stream E into the foot section 2 of the low pressure column. Alternatively, it is also possible to feed the material flow F directly into an upper region of the foot section 2

To transfer low pressure column.

In the air separation plant 100 shown here, the high-pressure column 1 and the foot section 2 of the low-pressure column are arranged in a column-type cool box 10, the head section 3 of the low-pressure column in a further column-type cool box 20 and the crude argon column 4 in a further column-type cool box 30. Mainly to accommodate the

Lines 6, a separate line cold box 40 is provided. The lines 6 can be subdivided into lines which are at least partially accommodated with vertical sections in the line gold box ("second

Lines ") and those that are optionally arranged therein (" first lines "). The first lines include those in the head region of the foot section 2 of the

Low pressure column open, which lead to the material flows C and D and E, and a line that gas from an evaporation chamber of the top condenser 4a

Crude argon column 4 (and possibly from an evaporation chamber of the top condenser 5a of the pure argon column 5) is transported into the top section 3 of the low-pressure column, as illustrated here in the form of a material flow K. The other lines belong to the "second lines".

The pure argon column 5 is arranged here together with the raw argon column 4 in the common column cool box 30. A supercooling counterflow 7 is in the

Air separation plant 100 along with at least part of the vertical

Sections of the second lines are arranged in the separate piping gold box 40. Liquid air S can be fed into the high-pressure column 1. Gaseous pressurized nitrogen T from the high pressure column 1 can be used as products

Low-pressure nitrogen U from the head section 3 of the low-pressure column,

internally compressed gaseous pressurized oxygen V, so-called impure nitrogen W, liquid nitrogen X, liquid oxygen Y and liquid argon Z are provided. The gaseous media are particularly in the main heat exchanger

Air separation plant warmed up. Gas can be withdrawn from the pure argon column 5 and released into the atmosphere.

FIG. 2 shows an air separation plant, which is set up for operation according to a further embodiment of the present invention, in a greatly simplified partial illustration. This air separation plant also includes other components. It is given here in a highly simplified form with 200. To the components of the

Air separation plant 200, which are illustrated here with identical reference numerals as in FIG. 1, is also referred to technical literature and to the explanations for FIG. 1. Only the differences are explained below.

The air separation unit 200 differs from the air separation unit 100 essentially in that at least some of the vertical sections of the second lines are arranged in a line cold box 20a, in which the head section 3 of the low-pressure column is also arranged. In the example shown, the line cold box 20a also contains the subcooling counterflow 7. In contrast to the illustration in FIG. 2, the subcooling counterflow 7 can in particular be arranged below the head section 3 of the low-pressure column. This is possible in particular due to the lower height of the head section 3 of the low-pressure column in comparison to a predominant part of the other separation units in the air separation plant 200, in particular if a lower one is in the head section 3

Packing density is used.

FIG. 3 shows an air separation plant, which is set up for operation according to a further embodiment of the present invention, in a greatly simplified partial illustration. This air separation plant also includes other components. It is given here in a highly simplified form with 300. To the components of the

Air separation plant 300, here with identical reference numerals as in FIGS. 1 and 2 are also referred to technical literature and to the explanations for Figures 1 and 2. Only the differences are explained below.

The air separation plant 300 differs from the air separation plants 100 and 200 essentially in that here the raw argon column 4 is arranged alone in a column cold box 30a, and in that the pure argon column 5 is arranged here in a line cold box 40a provided primarily for receiving the explained sections of the second lines , In the example shown, the line cold box 40a also contains the supercooling counterflow 7. In contrast to the illustration in FIG. 3, the supercooling counterflow 7 can be arranged in particular below the pure argon column 5. This is possible in particular due to the lower height of the pure argon column compared to the predominant part of the other separation units of the air separation plant 300.

As illustrated in the form of the linkage P, the material flow D 'is first led into the head section 3 of the low pressure column and a part in the form of the material flow C is removed from it and fed into the crude argon column 4.

FIG. 4 shows an air separation plant, which is set up for operation according to a further embodiment of the present invention, in a greatly simplified partial illustration. This air separation plant also includes other components. It is given here in a highly simplified form at 310. In contrast to the air separation plant 300, no combination of raw and pure argon column is provided here. Rather, a modified crude argon column 4, which has been explained several times, is provided, from which a pure argon stream L is already removed. Therefore, no pure argon column 5 is arranged here in the line gold box 4a.

Figure 5 illustrates in views 5a to 5d arrangements of cold boxes in an air separation plant according to an embodiment of the present invention. The air separation plant can correspond in particular to the air separation plant 100 according to FIG. 1, but a corresponding arrangement can also be used with others

Air separation plants are used as the air separation plant 100, in particular in an air separation plant in which only one argon recovery column is used instead of a combination of raw argon column 4 and pure argon column 5. 5 shows top views of cold boxes 10 to 40 without the respective separation units illustrates, with another cold box containing a main heat exchanger (indicated in Figure 5a with 8 and omitted in the other views for the sake of clarity), designated 90. The cold box 90 was also referred to above as the "main heat exchanger cold box".

First to fourth side surfaces of the fourth cold box 40 are indicated by 41 to 44. A first column gold box 10 (with the high pressure column 1 and the foot section 2 of the low pressure column), a line gold box 40 and the main heat exchanger gold box 90, which contains the main heat exchanger 8 of the air separation unit 100, are arranged in all views 5a to 5d in such a way that the first side surface 41 closes the main heat exchanger cool box 90 and the second side surface 43 to the

Column box 10 points. A second column gold box 20 (with the head section 3 of the low pressure column) and a third column gold box 30 (with the argon recovery column) can be arranged differently, in such a way that the third side surface 43 faces the second column gold box 20 and the fourth side surface 44 faces the third column gold box 30 points, as illustrated in view 5a, or that the third side surface 43 faces the third pillar gold box 30 and the fourth side face 44 faces the second pillar gold box 20, as illustrated in view 5b, or that the third side surface 43 faces the second pillar gold box 20 and the third pillar gold box 30 faces as illustrated in view 5c, or that the fourth side surface 44 faces the second pillar gold box 20 and the third pillar gold box 30 as illustrated in view 5d.

Figure 6 illustrates arrangements of cold boxes in air separation plants according to further embodiments of the present invention. The air separation plants are labeled 400 to 700 and are also illustrated in a simplified top view with the omission of other essential components.

In the air separation plant 400, all of the separation units, namely the high-pressure column 1, the foot section 2 of the low-pressure column, the head section 3 of the low-pressure column and the crude argon column 4 with the pure argon column 5 are arranged in a common column cool box, which is indicated here at 50. Furthermore, the separate line gold box 40 is provided here. In the air separation plants 500 and 600, on the other hand, the high-pressure column 1 and the foot section 2 of the low-pressure column are together with a further separating unit in a common manner Column gold box 60, 70 arranged, the remaining separation unit is arranged in a further column gold box 20, 30. In the air separation plant 700 and 600, on the other hand, only the high-pressure column 1 and the foot section 2 of the low-pressure column are arranged together in a common column gold box 10, the remaining separation units are jointly arranged in a further column gold box 80. The line gold box 40 is also provided here in each case. For the respective elements, which are provided here with identical reference numerals as before, reference is expressly made to the above statements. FIG. 7 illustrates arrangements of cold boxes in air separation plants according to further embodiments of the present invention. The air separation plants are also illustrated here in a simplified top view, leaving out other essential components. A line cold box 40 is provided in each case, with all of the separation units, namely the high-pressure column 1, the foot section 2 of the low-pressure column, in the arrangement shown on the left in FIG

Head section 3 of the low pressure column and the raw argon column 4 with the

Pure argon column 5 are arranged in a common column gold box, which is also indicated here with 50, to which the line gold box 40 directly adjoins. The pillar gold box and the line gold box 40 can in particular be connected to one another at their corresponding surfaces. In the view shown on the right in FIG. 7, a corresponding pillar gold box, here designated 50 ', is L-shaped and the piping gold box 40 is fitted into the pillar gold box 50' in the manner shown.

Claims

claims

1. Air separation plant (100-700) with four separation units (1-4) in the form of one

High-pressure column (1), a foot section (2) of a two-part low pressure column, a head section (3) of the two-part one

Low pressure column and a one-piece argon recovery column (4) which has a top condenser (5a), the four separation units (1-4) at least partly by means of lines (6) with one another and / or at least partly by means of lines (6) with or are connected to a plurality of further apparatuses (7, 8), the lines (6) comprising one or more first lines and a number of second lines, and the one or more first lines comprising one or more lines which are located in a head region of the

Bottom section (2) of the low pressure column, and / or a line which opens into a gas space of a top condenser (5a) of the argon recovery column (4), is characterized in that the top section (3) of the low pressure column has a smaller cross section than that Has foot section (2) of the low-pressure column, and that vertically running sections of the second lines are at least partially accommodated in a cold box (20a, 40, 40a), which is a column-type cold box (20a) in which the head section (3) of the low-pressure column is arranged , or as a separate line gold box (40, 40a), in which none of the four separation units (1-4) is arranged.

2. Air separation plant (100-700) according to claim 1, wherein one or more

vertical sections of the first line or the plurality of first lines also at least partially in the cold box (20a, 40, 40a)

is or are housed, in which the vertical sections of the second lines are at least partially housed.

3. Air separation plant (100-700) according to claim 1 or 2, in which the separate line cold box (40, 40a) is provided, and in which

- A common Säulencoldbox (50) is provided, in which all of the four separation units (1-4) are accommodated, or - A common Säulencoldbox (60-80) is provided in which the

High-pressure column (1), the foot section (2) of the low-pressure column and exactly one more of the four separation units (1-4) are accommodated, a further column cool box (30) being provided in which the remaining of the four separation units (1-4) is accommodated is, or

- A common Säulencoldbox (10) is provided in which the

The high-pressure column (1) and the foot section (2) of the low-pressure column are accommodated, a further common column-cool box (80) being provided, in which the two remaining four separation units (1-4) are accommodated, or

- A common Säulencoldbox (10) is provided in which the

High-pressure column (1) and the foot section (2) of the low-pressure column are accommodated, with two further column-shaped gold boxes (20, 30)

are provided, in which one of the two remaining four separation units (1-4) is accommodated.

4. Air separation plant (100-700) according to claim 3, wherein a raw argon column as the argon recovery column and a pure argon column (5) as a fifth

Separation unit are provided, the pure argon column (5) in the

Line cold box (40a) or in that of the column gold boxes (50, 60, 80)

is recorded in the crude argon column (4).

5. Air separation plant (100-700) according to Claim 3, in which a separation unit set up for enriching or obtaining a krypton / xenon or helium / neon mixture is provided as a fifth separation unit (5), this fifth separation unit (5) in the line cold box (40a) or in that of

Column gold boxes (50, 60, 80) is accommodated in the argon extraction column (4) is accommodated.

6. Air separation plant (100-700) according to one of claims 3 to 5, in which a separate main heat exchanger cool box (90) is provided, in which the main heat exchanger (8) of the air separation plant (100) is accommodated, wherein one of the side surfaces (41) of the line gold box (40) is arranged parallel to a side surface of the main heat exchanger gold box (90).

7. Air separation plant (100-700) according to claim 6, wherein at least one further of the side surfaces (42-43) of the line gold box (40) in each case assigns a side surface to one of the column gold boxes (10-80).

8. Air separation plant (100-700) according to one of the preceding claims, in which the separate line cold box (40, 40a) is provided and in which it has a size of less than 6 meters in an extension direction.

9. Air separation plant (100-700) according to one of the preceding claims, in which the separate line cold box (40, 40a) is provided and in which one

Hypothermia counterflow (7) is arranged in the line cold box (40, 40a).

10. Air separation plant (100-700) according to one of the preceding claims, in which the separate line cold box (40, 40a) is provided and in which this in a first direction parallel to the vertical sections of the second lines is at least a factor of 5 larger Extends as in the directions vertical to this.

1 1. Air separation plant (100-700) according to one of the preceding claims, in which a packing density in the head section (3) of the low pressure column at less than 600 m ² / m ³ and in the foot section (2) of the low pressure column at more than 300 m ² / m ³ lies.

12. Air separation plant (100-700) according to one of the preceding claims, in which one for fluid transfer between a lower region of the head section (3) of the low-pressure column and an upper region of the foot section (2) of the

Low pressure column, a transfer pump or a plurality of transfer pumps arranged in parallel and / or provided redundantly are provided.

13. Air separation plant (100-700) according to one of the preceding claims, in which a first packing area with a first packing density is formed in a lower area of the foot section (2) of the low-pressure column and in which the argon recovery column (4) has a second packing area with a second packing density, the first packing density being less than 1,000 square meters per cubic meter and the second packing density being more than 750 square meters per cubic meter and the second packing density being more than 250 square meters per cubic meter is the first packing density.

14. A method for the low-temperature separation of air, characterized in that an air separation plant (100-700) according to one of the preceding claims is used, wherein air is fed into the high-pressure column (1), in the high-pressure column (1) a bottom liquid with an oxygen content of 30 to 50 mole percent is formed and at least partially transferred into the top section (3) of the low pressure column, a top gas is formed in the bottom section (2) of the low pressure column and at least partially into the argon recovery column (4) and / or into the top section (3) of the low pressure column is transferred, and a bottom liquid is formed in the argon recovery column (4) and at least partially transferred into the top section (2) of the low-pressure column.

15. A method for creating an air separation plant (100-700) according to any one of claims 1 to 13, in which four separation units (1-4) in the form of a

High-pressure column (1), a foot section (2) of a two-part low-pressure column, the head section (3) of the two-part one

Low pressure column and a one-piece argon recovery column (4), which has a top condenser (5a), and the four separation units (1- 4) at least partly by means of lines (6) and / or at least partly by means of lines (6) to one or are connected to a plurality of further apparatuses (7, 8), the lines (6) comprising one or more first lines and a number of second lines, the one or more first lines comprising one or more lines which are located in a head region of the

Bottom section (2) of the low-pressure column, and / or a line which opens into a gas space of a top condenser (5a) of the argon recovery column (4), characterized in that the top section (3) of the low-pressure column has a smaller cross section than that Has foot section (2) of the low pressure column, and that vertically extending sections of the second lines are at least partially accommodated in a cold box (20a, 40, 40a), which is a column-shaped gold box (20a) in which the head section of the Low pressure column is arranged, or as a separate line cold box (40, 40a), in which none of the four separation units (1-4) is arranged.